Cyclic life establishment of the compressor disc of a gas turbine engine

Gas turbine engines for fighter class aircrafts are having unique characteristics. It is not uncommon that gas turbine engine with deep throttles both during acceleration and deceleration not only consumes life but also deficiencies are manifested out in the form of defects. In this project, the dictum is to carry out a cyclic life analysis of a compressor disc which is already flying along with the fighter class engine fitted on a fighter class aircraft. Since both the geometrical drawing and the boundary conditions of the discs are known, a model is therefore prepared using the modeling software (CATIA). The discretized model is then subjected to analysis using ANSYS software and the maximum stress values and its locations were identified for all the RPM conditions of the engine. Alternating stresses are acquired from Goodman diagram and cyclic life is obtained from S-N diagram. Modal analysis is carried out for bending and umbrella mode and the values are superposed on Campbell diagram, to arrive at the resonances with the engine order. Efforts are also made to simulate defect in the component and the modes are captured to identify the resonance characteristics of the component with defects.